Removal processing apparatus and removal processing method

Abstract

To provide a removal processing device and a removal processing method capable of preventing excessive removal when manually removing a part of a workpiece.SOLUTION: An NC grinding device 10 includes a display control unit 25 that, in accordance with movement of a grinding wheel 35, displays a position of a grinding wheel contour line on a display 12 in synchronization with a position of the grinding wheel 35. The NC grinding device 10 further includes a determination unit 26 that determines whether or not a separation distance between a target work contour line and the grinding wheel contour line is equal to or less than a removal-prohibited separation distance. When the determination unit 26 determines that the separation distance is equal to or less than the removal-prohibited separation distance, an NC control unit 29 stops the grinding wheel 35 even if an operation to move the grinding wheel contour line toward the target work contour line is performed on an X-axis handle 17a and a Y-axis handle 18a.SELECTED DRAWING: Figure 1

Description

Technical Field

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[0001] The present invention relates to a removal processing apparatus and a removal processing method.

Background Art

[0002] Conventionally, as described in, for example, Patent Document 1 and Patent Document 2, a series of operations related to grinding by a NC grinding apparatus are programmed in advance based on numerical information such as the position and speed regarding the relative movement between a workpiece and a grinding wheel. Then, according to the commands of this program, the NC grinding apparatus executes grinding of the workpiece by the grinding wheel

[0003] In such grinding by a NC grinding apparatus, usually, rough machining is performed first, and then finish machining is performed. In order to remove a large amount of stock in a short time, rough machining may be performed by manually operating the grinding apparatus.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] When manually operating the grinding apparatus as described above, an operator often performs rough machining while visually checking a display on which a projected image of the workpiece and the grinding wheel enlarged using a projector is displayed.

[0006] However, even when checking the projected image, there is a risk of over-grinding the workpiece due to, for example, a work mistake or a judgment mistake caused by lack of attention. The object of the present invention is to provide a removal processing apparatus and a removal processing method that prevent excessive removal when removing a portion of a workpiece by manual operation. [Means for solving the problem]

[0007] To solve the above problems, the removal processing apparatus of the present invention comprises: a removal tool for removing a part of a workpiece; a display unit that displays a removal tool contour line, which is the contour line of the removal tool, and a target workpiece contour line, which is the contour line of the workpiece after processing; a manual operation unit operated by an operator to move the removal tool; a control unit that moves the removal tool based on an operation performed on the manual operation unit; a display control unit that displays the position of the removal tool contour line on the display unit in synchronization with the position of the removal tool in accordance with the movement of the removal tool; and a determination unit that determines whether the separation distance between the target workpiece contour line and the removal tool contour line is less than or equal to the removal prohibition separation distance. If the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the control unit stops the removal tool even if an operation is performed on the manual operation unit to move the removal tool contour line in a direction that brings it closer to the target workpiece contour line.

[0008] According to the above configuration, if the separation distance is less than or equal to the removal prohibition separation distance, the control unit will stop the removal tool even if the manual operation unit performs an operation to move the removal tool contour line in the direction that brings it closer to the target workpiece contour line, i.e., an operation that moves the removal tool in the direction that brings it closer to the workpiece. As a result, when removing a part of the workpiece by manual operation, excessive removal is prevented.

[0009] In the above-described removal processing apparatus, if the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the display control unit may highlight at least a portion of the target workpiece contour line.

[0010] Here, "highlighting" refers to emphasizing or highlighting. This includes changing the color, line thickness, brightness, and line type. When changing the color, it is preferable to change it to a brighter color than before. When changing the line thickness, it is preferable to make it thicker than before. When changing the brightness, it is preferable to increase the brightness compared to before.

[0011] The target workpiece contour and removal tool contour include shape contours. Shape contours include lines used as elements for shape representation, and groups of lines that represent the whole or part of the shape of the object itself. Lines used as elements for shape representation include straight lines, dotted lines, dashed lines, curves, etc.

[0012] According to the above configuration, the operator can be notified that the removal tool has been stopped by highlighting at least a portion of the target workpiece contour line. In the removal processing apparatus described above, the determination unit further determines whether the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance which is greater than the removal prohibition separation distance, and the control unit is configured to move the removal tool faster the faster the operation performed on the manual operation unit is, and when the determination unit determines that the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance, the control unit limits the movement speed of the removal tool compared to when the determination unit determines that the separation distance is greater than the caution separation distance.

[0013] According to the above configuration, if the separation distance is greater than the removal prohibition separation distance but less than or equal to the caution separation distance, the movement speed of the removal tool is restricted. As a result, when the removal tool approaches the workpiece from a state where it is somewhat close to the workpiece, the movement speed of the removal tool is restricted. This suppresses the movement of the removal tool due to inertia when the removal tool is stopped because the separation distance becomes less than or equal to the removal prohibition separation distance.

[0014] In the above-described removal processing apparatus, when the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the display mode in which at least a portion of the target workpiece contour line is highlighted is the first display mode. When the determination unit determines that the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance, the display control unit may highlight at least a portion of the target workpiece contour line in a second display mode different from the first display mode.

[0015] According to the above configuration, if the separation distance is greater than the removal prohibition separation distance but less than or equal to the caution separation distance, at least a portion of the target workpiece contour line is highlighted in a second display mode different from the first display mode. This allows the operator to be notified to stop the removal tool.

[0016] The first display mode is a display mode consisting of one of the above-mentioned emphasis expressions or a combination thereof. The second display mode is a display mode consisting of one of the above-mentioned emphasis expressions or a combination thereof, and is different from the first display mode.

[0017] The above-described removal processing apparatus further includes an imaging unit that images the workpiece and the removal tool to acquire actual images of the workpiece and the removal tool, and the display control unit may display the actual workpiece image superimposed on the target workpiece contour line and the actual removal tool image superimposed on the removal tool contour line on the display unit.

[0018] With the above configuration, the actual workpiece image is superimposed on the target workpiece contour line, and the actual removal tool image is superimposed on the removal tool contour line, so that the removal process on the workpiece by the removal tool can be visually confirmed more realistically.

[0019] Also, in order to solve the above problems, according to the present invention, a removal processing method in a removal processing apparatus is provided. The removal processing apparatus includes a removal tool for removing a part of a workpiece, a display unit for displaying a removal tool contour line which is a contour line of the removal tool and a target workpiece contour line which is a contour line of the workpiece after processing, and a manual operation unit which is operated by an operator to move the removal tool. The removal processing method includes moving the removal tool based on an operation performed on the manual operation unit, synchronously displaying the position of the removal tool contour line in the display unit in synchronization with the position of the removal tool in response to the movement of the removal tool, determining whether a separation distance between the target workpiece contour line and the removal tool contour line is less than or equal to a removal prohibited separation distance, and stopping the removal tool even if an operation to move the removal tool contour line in a direction approaching the target workpiece contour line, that is, an operation to move the removal tool in a direction approaching the workpiece, is performed on the manual operation unit when it is determined that the separation distance is less than or equal to the removal prohibited separation distance.

[0020] According to the above configuration, when the separation distance is the removal prohibited separation distance, the removal tool stops even if an operation to move the removal tool contour line in a direction approaching the target workpiece contour line, that is, an operation to move the removal tool in a direction approaching the workpiece, is performed on the manual operation unit. Therefore, when removing a part of the workpiece by manual operation, the occurrence of excessive removal is prevented.

Effect of the Invention

[0021] The removal processing apparatus and the removal processing method of the present invention can prevent the occurrence of excessive removal when removing a part of a workpiece by manual operation.

Brief Description of the Drawings

[0022] [Figure 1] It is a configuration diagram showing an outline of an NC grinding apparatus according to an embodiment. [Figure 2] It is a flowchart of a grinding wheel contour line creation program executed by the CPU of the NC grinding apparatus in FIG. 1. [Figure 3](a) is an explanatory diagram of a state where a grinding wheel approaches a dummy workpiece in the NC grinding apparatus of FIG. 1, (b) is an explanatory diagram of a state where the dummy workpiece is being machined by cutting with the grinding wheel in the NC grinding apparatus of FIG. 1, and (c) is an explanatory diagram of a grinding wheel shape transfer position button displayed on the display of the NC grinding apparatus of FIG. 1. [Figure 4] (a) is an explanatory diagram when the specifications of the grinding wheel included in the NC grinding apparatus of FIG. 1 are "right β degrees", (b) is an explanatory diagram when the specifications of the grinding wheel are "left β degrees", (c) is an explanatory diagram when the specifications of the grinding wheel are "both V, β degrees", and (d) is an explanatory diagram of the turning angle of the grinding wheel with respect to the workpiece. [Figure 5] (a) is an explanatory diagram of a grinding wheel profile generation button displayed on the display of the NC grinding apparatus of FIG. 1, and (b) is an explanatory diagram of a state where a grinding wheel contour line is superimposed on a real grinding wheel image and displayed on the display of the NC grinding apparatus of FIG. 1. [Figure 6] (a) is an explanatory diagram of an AR grinding wheel display ON button displayed on the display of the NC grinding apparatus of FIG. 1, (b) is an explanatory diagram of a state where a real grinding wheel image is displayed on the display of the NC grinding apparatus of FIG. 1, and (c) is an explanatory diagram of a state where a grinding wheel contour line is superimposed on a real grinding wheel image and displayed on the display of the NC grinding apparatus of FIG. 1. [Figure 7] It is an explanatory diagram of a setting menu displayed on the screen of the display of the NC grinding apparatus of FIG. 1. [Figure 8] It is the first half of a flowchart of a removal processing stop program executed by the CPU of the NC grinding apparatus of FIG. 1 when performing removal processing manually. [Figure 9] It is the second half of a flowchart of the removal processing stop program of FIG. 8. [Figure 10] (a) is an explanatory diagram of a state where the tip of the grinding wheel contour line has not reached the caution position line on the display of the NC grinding apparatus of FIG. 1, (b) is an explanatory diagram of a state where the tip of the grinding wheel contour line has reached the caution position line but has not reached the stop position line on the display of the NC grinding apparatus of FIG. 1, and (c) is an explanatory diagram of a state where the tip of the grinding wheel contour line has reached the stop position line on the display of the NC grinding apparatus of FIG. 1. [Modes for carrying out the invention]

[0023] (Embodiment) Hereinafter, an embodiment of the removal processing apparatus and removal processing method of the present invention will be described with reference to Figures 1 to 10(c).

[0024] (1. Schematic configuration of the NC grinding machine 10) As shown in Figure 1, the NC grinding machine 10, which is a removal processing device, comprises a control device 11, a display 12, input devices such as a pendant 14 and a mouse 16, and a grinding unit 30.

[0025] (2. Control device 11) The control device 11 consists of a computer and includes a CPU (Central Processing Unit) 22 and a storage unit 24 equipped with ROM, RAM, and a hard disk, etc.

[0026] The memory unit 24 stores the NC program. The NC program is read and executed by the CPU 22 during automatic grinding. Furthermore, the memory unit 24 stores a grinding wheel contour creation program and a removal process stop program.

[0027] The grinding wheel contour creation program is loaded into the CPU 22 and executed. By executing the grinding wheel contour creation program, the CPU 22 functions as an image processing unit 27 and a grinding wheel contour creation unit 28.

[0028] Furthermore, the removal process stop program is loaded into the CPU 22 and executed. By executing the removal process stop program, the CPU 22 functions as the display control unit 25, the determination unit 26, and the NC control unit 29.

[0029] The CPU 22 functions as the NC control unit 29 by executing the NC program. RAM is working memory. The NC control unit 29 corresponds to the control unit. The hard disk stores shape drawing data for multiple workpieces, as well as grinding wheel contour line image data, in a writable and readable format.

[0030] (Regarding the outline of the target work) The workpiece shape drawing data is saved, for example, in a DXF file format that can be read and written by CAD software. Note that the workpiece shape drawing data is not limited to a DXF file format; other file formats may also be used. In this embodiment, the workpiece shape drawing data is formed in DXF format.

[0031] Furthermore, the shape drawing data for the workpiece may be shape drawing data formed from a template. The template includes pre-set shape data such as combinations of shapes like lines, circles, arcs, rectangles, and triangles, or individual shape data. When forming shape drawing data from a template, a shape such as a straight line or a circle is selected on the screen 13 of the display 12 using a template selection button (not shown). As a result, the shape of the selected template is drawn on the screen 13. Then, the shape drawing data is formed by editing this template shape. The formed shape drawing data is stored in an image memory configured with RAM.

[0032] The display control unit 25 displays the target workpiece contour line B on the display 12 based on shape drawing data formed in DXF format or shape drawing data formed from a template stored in image memory. The display 12 corresponds to the display unit. The target workpiece contour line B is the contour line of the workpiece after it has been processed into the desired shape by grinding. The target workpiece contour line B may also be created by extracting the contour line from an actual image of the processed workpiece using image processing such as edge detection.

[0033] The target workpiece contour line B has points of change in shape. These points of change in shape include points where straight lines are connected to each other, points where straight lines are connected to each other, or points where arcs are connected to each other. Thus, the straight lines and arcs that form these points of change are "elements" that form the target workpiece contour line B. Note that arcs correspond to curves.

[0034] (Regarding the outline of the grinding wheel) Grinding wheel contour image data represents the shape data of the grinding wheel. The grinding wheel contour image data is extracted from images of grinding marks on a dummy workpiece ground by the grinding wheel, using image processing such as edge detection. In the following text, the contour of the grinding wheel contour image data will simply be referred to as grinding wheel contour A1. Details on the creation of grinding wheel contour A1 will be described later. Grinding marks correspond to removal marks.

[0035] (3. Display 12) The display 12 consists of a liquid crystal display device, an organic EL display device, or a CRT, and is capable of color display. The display 12 is a touch panel display. As shown in Figure 1, the screen 13 of the display 12 has an image display area 13a, a button display area 13b, and a panel area (not shown), etc. The image display area 13a is set to an XY coordinate system that corresponds to the machine coordinate system of the grinding mechanism 31.

[0036] (4. Input device) The pendant 14 is equipped with various operation buttons, etc. The mouse 16 is an input device that moves a mouse pointer (not shown) on the screen 13 shown in Figure 1. The X-axis operation device 17 is equipped with an X-axis handle 17a and an encoder 17b. When the X-axis handle 17a is manually rotated clockwise or counterclockwise, the encoder 17b outputs a pulse signal corresponding to that operation to the CPU 22 of the control device 11. Note that the pulse signal is sometimes called an operation signal.

[0037] The NC control unit 29 moves the grinding wheel 35 in the +X or -X direction of the machine coordinate system of the grinding mechanism 31 by controlling, for example, the X-axis motor 37, which will be described later, based on the pulse signal. For example, rotating the X-axis handle 17a to the right corresponds to moving the grinding wheel 35 in the -X direction, and rotating the X-axis handle 17a to the left corresponds to moving the grinding wheel 35 in the +X direction. The grinding wheel 35 corresponds to the removal tool.

[0038] Based on the pulse signal, the display control unit 25 displays the position of the grinding wheel contour line A1 displayed on the image display area 13a of the screen 13 in synchronization with the grinding wheel 35, for example, in the +X direction or -X direction of the mechanical coordinate system of the grinding mechanism 31. In other words, the display control unit 25 moves the grinding wheel contour line A1 on the image display area 13a in the same way as the movement of the grinding wheel 35. The mechanical coordinate system of the grinding mechanism 31 is the same as the mechanical coordinate system of the NC grinding device 10.

[0039] The Y-axis operating device 18 includes a Y-axis handle 18a and an encoder 18b. When the Y-axis handle 18a is manually rotated clockwise or counterclockwise, the encoder 18b outputs a pulse signal corresponding to that operation to the CPU 22. Based on the pulse signal, the NC control unit 29 controls, for example, the Y-axis motor 38 (described later), to move the grinding wheel 35 in the +Y or -Y direction of the machine coordinate system of the grinding mechanism 31. For example, rotating the Y-axis handle 18a clockwise corresponds to moving the grinding wheel 35 in the -Y direction, and rotating the Y-axis handle 18a counterclockwise corresponds to moving the grinding wheel 35 in the +Y direction.

[0040] Furthermore, based on the pulse signal, the CPU 22 displays the position of the grinding wheel contour line A1 displayed in the image display area 13a of the screen 13 in synchronization with the grinding wheel 35, for example, in the +Y direction or -Y direction of the mechanical coordinate system of the grinding mechanism 31. In other words, the display control unit 25 moves the grinding wheel contour line A1 on the image display area 13a in the same way as the movement of the grinding wheel 35.

[0041] The X-axis handle 17a of the X-axis operating device 17 and the Y-axis handle 18a of the Y-axis operating device 18 correspond to the manual operation section. The encoder 17b of the X-axis operating device 17 and the encoder 18b of the Y-axis operating device 18 correspond to the operation amount detection section.

[0042] Furthermore, when both handles 17a and 18a are operated simultaneously, the grinding wheel and the grinding wheel contour can be moved in a direction that is a combination of the X and Y directions. (5. Grinding section 30) As shown in Figure 1, the grinding unit 30 comprises a grinding mechanism unit 31, a workpiece holding mechanism unit 32, a moving mechanism unit 33, and an imaging unit 39.

[0043] The grinding mechanism 31 is equipped with a disc-shaped grinding wheel 35. The grinding mechanism 31 performs grinding on the workpiece W held by the workpiece holding mechanism 32. During grinding, the grinding mechanism 31 rotates the grinding wheel 35.

[0044] The workpiece holding mechanism 32 detachably holds the workpiece W. The workpiece holding mechanism 32 can also detachably hold a dummy workpiece (not shown) in place of the workpiece W. The workpiece holding mechanism 32 is mounted on the XY table 134 and is capable of moving the workpiece W in the X and Y directions. It is equipped with an X-axis operating device 120 and a Y-axis operating device 122 for moving the XY table 134 in the X and Y directions.

[0045] The X-axis operating device 120 is equipped with a manual handle 120a and an encoder 120b. When the manual handle 120a is operated, the encoder 120b outputs an operation signal corresponding to that operation to the CPU 22.

[0046] The NC control unit 29 of the CPU 22 operates the XY table 134 based on the operation signal to move the workpiece holding mechanism 32 in the X direction of the machine coordinate system of the XY table 134. The Y-axis operating device 122 is equipped with a manual handle 122a and an encoder 122b. When the manual handle 122a is operated, the encoder 122b outputs an operation signal corresponding to that operation to the CPU 22. Based on the operation signal, the NC control unit 29 operates the XY table 134 to move the workpiece holding mechanism 32 in the Y direction of the machine coordinate system of the XY table 134.

[0047] The grinding mechanism 31 is located in the moving mechanism 33 and causes the grinding wheel 35 to move relative to the workpiece W. The moving mechanism 33 is equipped with an X-axis motor 37, a Y-axis motor 38, and a Z-axis motor 36. The X-axis motor 37 and Y-axis motor 38 are controlled by the NC control unit 29, allowing the grinding wheel 35 to move along the X and Y axes. In addition, the grinding wheel 35 can oscillate within a predetermined range in the vertical direction (along the Z axis) by driving the Z-axis motor 36.

[0048] The imaging unit 39 is positioned above the workpiece W or dummy workpiece held by the workpiece holding mechanism 32. The imaging unit 39 is composed of a CMOS camera or a CCD camera. The imaging unit 39 has the height of the upper end surface of the workpiece W or dummy workpiece as its focal point. The imaging unit 39 transmits a video of the cutting process, including rough machining of the workpiece W by the grinding wheel 35, or a still image of the grinding marks on the dummy workpiece cut by the grinding wheel 35, to the image processing unit 27.

[0049] <1. Creating the grinding wheel outline> Figure 2 is a flowchart of the grinding wheel contour creation program. The grinding wheel contour creation program is executed by the CPU 22 when a dummy workpiece is processed with the grinding wheel 35. Before the grinding wheel contour creation program is executed, the operator stores the specifications of the grinding wheel 35 in the memory unit 24 by entering them into the various input fields in the button display area 13b. As shown in Figures 4(a) to 4(d), these specifications include the orientation of the side surface of the grinding wheel 35, the inclination angle β of the side surface, and the rotation angle γ relative to the workpiece.

[0050] In this embodiment, the tip of the grinding wheel 35 is rounded in an arc shape; however, the shape of the tip of the grinding wheel 35 is not limited to an arc shape. The grinding wheel 35 may be a flat grinding wheel with a square tip. A flat grinding wheel can perform grinding efficiently in rough machining.

[0051] The grinding wheel 35 can have three orientations for its sides: "right-leaning," "left-leaning," and "double V-shape." Figure 4(a) shows the grinding wheel 35 in the "right-leaning" state. "Right β degree" means that, when viewed from the workpiece, the right side of the grinding wheel 35 is inclined to the right at an angle β, relative to the left side of the grinding wheel 35. Figure 4(b) shows the grinding wheel 35 in the "left-leaning" state. "Left β degree" means that, when viewed from the workpiece, the left side of the grinding wheel 35 is inclined at an angle β, relative to the right side of the grinding wheel 35. Figure 4(c) shows the grinding wheel 35 in the "double V-shape." "Double V, β degree" means that, when viewed from the workpiece, the left and right sides of the grinding wheel 35 are inclined to the left and right, forming a V-shape, and the angle between the left and right sides of the grinding wheel 35 is "β." In Figure 4(d), "+γ degrees" and "-γ degrees" indicate how much the grinding wheel 35 has rotated to the right or left by a rotation angle γ, relative to the workpiece.

[0052] (S102) In step S102, as shown in Figure 3(a), grinding is performed on a dummy workpiece Wp held in the workpiece holding mechanism 32 using the grinding wheel 35. This machining of the dummy workpiece Wp is performed by the operator operating the X-axis handle 17a and the Y-axis handle 18a. Encoders 17b and 18b transmit operation signals to the CPU 22 in response to the operation of the X-axis handle 17a and the Y-axis handle 18a. Based on the transmitted operation signals, the NC control unit 29 drives the X-axis motor 37 and the Y-axis motor 38 to move the grinding wheel 35 in the X and Y directions. The CPU 22 also updates the XY coordinates of the grinding wheel 35 based on the transmitted operation signals.

[0053] As shown in Figure 3(b), the grinding marks Wc of the dummy workpiece Wp made by the grinding wheel 35 are captured by the imaging unit 39. The still image of the grinding marks Wc captured by the imaging unit 39 is called the grinding mark image. The grinding mark image is transmitted to the CPU 22. The grinding mark image corresponds to the removal mark image.

[0054] (S103) In S103, the operator touches the grinding wheel shape transfer position button 13c (see Figure 3(c)) displayed in the button display area 13b, thereby acquiring the XY coordinates of the grinding wheel 35 when grinding marks are formed.

[0055] These XY coordinates, i.e., the X and Y coordinate values, are the XY coordinates of the grinding wheel contour line A1, which will be created later. The XY coordinates of the grinding wheel contour line A1 are updated to be the same as the XY coordinates of the grinding wheel 35, which are updated in response to the operation of the X-axis handle 17a and the Y-axis handle 18a.

[0056] (S104) In S104, the image processing unit 27 performs image processing such as edge detection on the grinding mark image of the dummy workpiece grinding wheel 35. Through this image processing, contour lines are extracted, and the grinding wheel contour line is obtained. Each pixel of this grinding wheel contour line has XY coordinates.

[0057] This edge detection provides a grinding wheel contour line that matches the specifications of the grinding wheel 35 that were previously stored in the memory unit 24. Once edge detection is complete, the display control unit 25 prompts the operator to operate the grinding wheel contour generation button 13d (see Figure 5(a)) located in the button display area 13b by making it blink.

[0058] (S106) In S106, the operator touches the grinding wheel contour generation button 13d. As a result, the grinding wheel contour creation unit 28 creates grinding wheel contour data based on the edges detected by edge detection and stores the grinding wheel contour data in the storage unit 24.

[0059] <2. Displaying and hiding the grinding wheel outline> When performing rough machining on a workpiece W by manually operating the NC grinding machine 10, consider a case where the operator wants to overlay the grinding wheel contour line A1 onto the actual grinding wheel image Tg. The actual grinding wheel image Tg corresponds to the actual removal tool image. The grinding wheel contour line A1 corresponds to the removal tool contour line.

[0060] In this case, the operator touches the AR grinding wheel contour line display ON button 13e (see Figure 6(a)) located in the button display area 13b (see Figure 1). The display control unit 25 then reads the grinding wheel contour line data stored in the storage unit 24.

[0061] Then, as shown in Figure 5(b) or Figure 6(c), the display control unit 25 overlays the grinding wheel contour A1, based on this grinding wheel contour data, onto the portion of the grinding wheel actual image Tg displayed in the image display area 13a of the display 12. In this case, the display control unit 25 overlays the grinding wheel contour A1 onto the portion of the grinding wheel actual image Tg for each frame of the video.

[0062] When the display control unit 25 enlarges or reduces the actual grinding wheel image Tg on the screen of the display 12, it also enlarges or reduces the grinding wheel contour line A1 by the same magnification. Figure 5(b) shows the grinding wheel outline A1 superimposed on the actual grinding wheel image Tg when the grinding wheel 35 is positioned at the focal point of the imaging unit 39. For the sake of clarity, the outline of the grinding wheel image Tg is shown with a thick line, and the area inside the grinding wheel image Tg is shown with thick hatching to clearly indicate that the grinding wheel 35 is positioned at the focal point. Note that this hatching does not represent a cross-sectional view.

[0063] Figure 6(c) shows the grinding wheel contour line A1 superimposed on the actual grinding wheel image Tg when the grinding wheel 35 is not located at the focal point of the imaging unit 39. For the sake of explanation, the contour of the actual grinding wheel image Tg is shown as a point cloud, and the inner region of the actual grinding wheel image Tg is shown as a thin hatched line.

[0064] Furthermore, if the operator wants to remove the overlay display of the grinding wheel contour line A1 when it is displayed superimposed on the actual grinding wheel image Tg as described above, the operator touches the AR grinding wheel contour line display ON button 13e. Upon this touch operation, the display control unit 25 removes the grinding wheel contour line A1 from the image display area 13a, as shown in Figure 6(b). Figure 6(b) shows the actual grinding wheel image Tg with the grinding wheel contour line A1 hidden, compared to the state in Figure 6(c). In this way, the display and hiding of the grinding wheel contour line A1 can be done with a single touch by touching the AR grinding wheel contour line display ON button 13e.

[0065] (Color indication of grinding wheel outline A1) The color of the grinding wheel contour line A1 is predetermined. The color of the grinding wheel contour line A1 may be set to be different from the color of the actual grinding wheel image Tg. Alternatively, the color of the grinding wheel contour line A1 may be set to be different from the color of the actual workpiece image. Furthermore, the color of the grinding wheel contour line A1 may be set to be different from both the color of the actual grinding wheel image Tg and the color of the actual workpiece image.

[0066] For example, if the grinding wheel image Tg and the workpiece image are achromatic monochrome images, the grinding wheel outline A1 will be displayed in a chromatic color such as yellow, red, or blue. The color of the grinding wheel outline A1 is an example and not limiting.

[0067] <3. Stop highlighting and removing the grinding wheel outline> Next, the highlighting and removal process stop when performing rough machining on the workpiece W by manually operating the NC grinding device 10 will be explained with reference to Figures 7 and 10(a) to 10(c).

[0068] (Highlight display setting input field 90) When the NC grinding machine 10 is operated manually to perform rough machining on the workpiece W, if the operator operates the highlight display setting tab (not shown) in the button display area 13b, the highlight display setting input field 90 shown in Figure 7 will be displayed in the button display area 13b.

[0069] As shown in FIG. 7, the highlight display setting input field 90 has a highlight display field 91 and a detection width setting field 92. In the highlight display field 91, an AR grinding wheel vs. line button 93 and an X / Y-axis AUTOSTOP button 94 are displayed. The AR grinding wheel refers to the grinding wheel contour line A1. In the detection width setting field 92, a caution detection position input field 95 and a warning switching position input field 96 are displayed.

[0070] When the AR grinding wheel vs. line button 93 is turned on, it becomes possible to input detection widths m1 and m2 to the caution detection position input field 95 and the warning switching position input field 96, respectively. That is, the caution detection position input field 95 is an input field for setting a detection width m1 (see FIGS. 10(a) and 10(b)), which is the distance from the target workpiece contour line B (DXF line or template). The detection width m1 corresponds to the caution separation distance.

[0071] In the input field, a numerical value up to four decimal places in millimeters (mm) can be input using a numeric keypad (not shown) displayed on the screen 13. The warning switching position input field 96 is an input field for setting a detection width m2 (<m1) (see FIGS. 10(a) and 10(b)), which is the distance from the target workpiece contour line B (DXF line or template). The detection width m2 corresponds to the removal prohibited separation distance.

[0072] In the following description, a line separated from the target workpiece contour line B by the detection width m1 may be referred to as a caution position line C1. Also, a line separated from the target workpiece contour line B by the detection width m2 may be referred to as a stop position line C2. The caution position line C1 and the stop position line C2 are shown in FIG. 10 for convenience of explanation, but are not displayed in the image display area 13a.

[0073] The set detection widths m1 and m2 are stored in the storage unit 24 by the display control unit 25 and the NC control unit 29. (Execution of the removal processing stop program) Before executing the removal process stop program, the actual workpiece image Wg, the actual grinding wheel image Tg, and the target workpiece contour line B are first displayed in the image display area 13a. The target workpiece contour line B is displayed superimposed on the actual workpiece image Wg. The color of the target workpiece contour line B may be the same as that of the grinding wheel contour line A1, but it is preferable that it be different from the grinding wheel contour line A1 in order to distinguish it from the grinding wheel contour line A1. The display mode of the target workpiece contour line B in this state is called the normal display mode. As will be described later, the normal display mode can be said to be a display mode in which the target workpiece contour line B is not highlighted. In Figures 10(a) to 10(c), for the sake of explanation, the inner part of the contour of the grinding wheel image Tg and the inner part of the contour of the actual workpiece image Wg are shown by hatching.

[0074] The operator manually adjusts the target work contour line B onto the actual work image so that the entire target work contour line B is contained within the actual work image. The operator can also move the target work contour line B on the image display area 13a and overlay it onto the actual work image by operating, for example, an operation button (not shown) on the pendant 14.

[0075] Next, the operator inputs the detection widths m1 and m2 into the attention detection position input field 95 and the warning switching position input field 96 shown in Figure 7. After this, the operator touches the AR grinding wheel contour display ON button 13e (see Figure 6(a)) to display the grinding wheel contour. Then, by turning on the X / Y axis AUTOSTOP button 94, the CPU 22 executes the removal process stop program. Note that the AR grinding wheel contour display ON button 13e may be touched before inputting the detection widths m1 and m2.

[0076] By touching the AR grinding wheel contour line display ON button 13e, the grinding wheel contour line A1 is displayed superimposed on the contour portion of the actual grinding wheel image Tg displayed in the image display area 13a.

[0077] Note that the grinding wheel contour line A1 shown here was created based on a grinding wheel 35 with a "double V" orientation on its side surface (see Figure 4(c)). However, the grinding wheel contour line A1 may also be created based on a grinding wheel 35 with a side surface orientation other than "double V".

[0078] Figures 8 and 9 are flowcharts of the removal process stop program. This flowchart includes the processes from S202 to S228. Process S202 is executed only at the start of the removal process stop program, while processes from S204 onward are repeated at predetermined intervals.

[0079] (S202) In S202, CPU22 resets the values ​​of flags F1 and F2 to "0". Flag F1 is a status indicator flag that shows whether the tip of the grinding wheel contour line A1 has reached the attention position line C1. If the value of flag F1 is "0" (F1=0), it indicates that the tip of the grinding wheel contour line A1 has not reached the attention position line C1 (within the detection width m1 range from the target work contour line B). If the value of flag F1 is "1" (F1=1), it indicates that the tip of the grinding wheel contour line A1 has reached the attention position line C1 (within the detection width m1 range from the target work contour line B). In other words, if the value of flag F1 is "1", it indicates that the distance D from the tip of the grinding wheel contour line A1 to the target work contour line B is less than or equal to the detection width m1.

[0080] Flag F2 is a status indicator flag that shows whether the tip of the grinding wheel contour line A1 has reached the stop position line C2. If the value of flag F2 is "0" (F2=0), it indicates that the tip of the grinding wheel contour line A1 has not reached the stop position line C2 (within the detection width m2 range from the target work contour line B). If the value of flag F2 is "1" (F2=1), it indicates that the tip of the grinding wheel contour line A1 has reached the stop position line C2 (within the detection width m2 range from the target work contour line B). In other words, if the value of flag F2 is "1", it indicates that the distance D from the tip of the grinding wheel contour line A1 to the target work contour line B is less than or equal to the detection width m2.

[0081] (S204) In S204, the CPU22 acquires operation signals (pulse signals) for the X-axis handle 17a and Y-axis handle 18a from encoders 17b and 18b.

[0082] (S206) In S206, CPU22 reads the values ​​of flags F1 and F2. (S208) In S208, CPU22 determines the state of flags F1 and F2. CPU22 proceeds to S210 if the value of flag F1 is "0" and the value of flag F2 is "0", proceeds to S212 if the value of flag F1 is "1" and the value of flag F2 is "0", and proceeds to S214 if the value of flag F1 is "1" and the value of flag F2 is "1".

[0083] (S210) S210 is a process where the values ​​of flags F1 and F2 are both "0", and the grinding wheel contour line A1 (grinding wheel 35) is sufficiently far from the target workpiece contour line B. The CPU 22 moves the grinding wheel 35 in response to the operation signals (pulse signals) of the X-axis handle 17a and the Y-axis handle 18a, and moves the grinding wheel contour line A1 (AR grinding wheel) on the screen 13 in synchronization with the movement of the grinding wheel 35. That is, the CPU 22 moves the grinding wheel contour line A1 so that the state in which the grinding wheel contour line A1 is superimposed on the contour of the actual grinding wheel image Tg that moves along with the movement of the grinding wheel 35 is maintained.

[0084] Figure 10(a) shows the state in which the grinding wheel contour line A1 moves in a direction perpendicular to the target workpiece contour line B by operating the X-axis handle 17a and the Y-axis handle 18a. After moving the grinding wheel 35 in this manner, the CPU 22 proceeds to S216 of the program.

[0085] Here, the movement speed of the grinding wheel 35 in the X-axis direction is set to increase as the operating speed of the X-axis handle 17a, i.e., the pulse frequency of the pulse signal, increases. The movement speed of the grinding wheel 35 in the Y-axis direction is set to increase as the operating speed of the Y-axis handle 18a, i.e., the pulse frequency of the pulse signal, increases.

[0086] Furthermore, if the X-axis handle 17a and Y-axis handle 18a are not operated, that is, if no pulse signals are output from encoders 17b and 18b, the grinding wheel 35 will not be moved, and the grinding wheel contour A1 (AR grinding wheel) will not be moved either. Similarly, if no pulse signals are output from encoders 17b and 18b, the grinding wheel 35 will not be moved, and the grinding wheel contour A1 (AR grinding wheel) will not be moved either, in the processing of S212 and S214 described later.

[0087] If the values ​​of flags F1 and F2 are both "0", the grinding wheel contour A1 and the grinding wheel 35 can be moved at a speed corresponding to the operating speed of the X-axis handle 17a and the Y-axis handle 18a. Furthermore, there are no restrictions on the direction in which the grinding wheel 35 can move.

[0088] (S212) S212 is a process performed when the value of flag F1 is "1" and the value of flag F2 is "0", and the tip of the grinding wheel contour line A1 (grinding wheel 35) is approaching the target workpiece contour line B. In the process of S212, the CPU 22 moves the grinding wheel 35 in response to the operation signals (pulse signals) of the X-axis handle 17a and the Y-axis handle 18a, and moves the grinding wheel contour line A1 (AR grinding wheel) on the screen 13 in synchronization with the movement of the grinding wheel 35.

[0089] However, in the S212 process, the movement speed of the grinding wheel 35 is limited. Specifically, if the operating speed of the X-axis handle 17a is greater than or equal to the threshold speed, the movement speed of the grinding wheel 35 in the X-axis direction is limited to a threshold-corresponding speed corresponding to the threshold speed. Similarly, if the operating speed of the Y-axis handle 18a is greater than or equal to the threshold speed, the movement speed of the grinding wheel 35 in the Y-axis direction is limited to a threshold-corresponding speed. In other words, in the S212 process, the upper limit of the movement speed of the grinding wheel 35 is set to the threshold-corresponding speed.

[0090] Furthermore, as long as the operating speeds of the X-axis handle 17a and the Y-axis handle 18a are below the threshold speed, the movement speed of the grinding wheel 35 changes according to the operating speeds of the X-axis handle 17a and the Y-axis handle 18a.

[0091] After moving the grinding wheel 35 in this manner, the CPU 22 proceeds to S216 of the program's processing. There are no restrictions on the direction in which the grinding wheel 35 moves. (S214) S214 is a process performed when the value of flag F1 is "1" and the value of flag F2 is "1", and the tip of the grinding wheel contour line A1 (grinding wheel 35) is very close to the target workpiece contour line B. In the process of S214, if the operation signal (pulse signal) of the X-axis handle 17a and the operation signal (pulse signal) of the Y-axis handle 18a move the grinding wheel contour line A1 in a direction that brings it closer to the target workpiece contour line B, the CPU 22 stops the grinding wheel 35 and, in synchronization with the stopping of the grinding wheel 35, stops the grinding wheel contour line A1 (AR grinding wheel) on the screen 13. After this, the CPU 22 moves the processing of this program to S216.

[0092] On the other hand, if the operation signals (pulse signals) of the X-axis handle 17a and the Y-axis handle 18a move the grinding wheel contour line A1 away from the target workpiece contour line B, the CPU 22 moves the grinding wheel 35 in accordance with the operation signals and, in synchronization with the movement of the grinding wheel 35, moves the grinding wheel contour line A1 (AR grinding wheel) on the screen 13 away from the target workpiece contour line B. The CPU 22 can determine, for example, whether the operation signal moves the grinding wheel contour line A1 closer to the target workpiece contour line B, based on whether the operation signal indicates an operation to move the grinding wheel 35 in the - direction or an operation to move the grinding wheel 35 in the + direction. For example, the CPU 22 can determine that the grinding wheel contour line A1 moves closer to the target workpiece contour line B when the operation signal indicates an operation to move the grinding wheel 35 in the - direction. The CPU 22 then proceeds to S216 of the program's processing.

[0093] In this case, the movement speed of the grinding wheel 35 by operating the X-axis handle 17a and the Y-axis handle 18a is limited to below the threshold speed. In other words, when the operating speed of the X-axis handle 17a and the Y-axis handle 18a is equal to or greater than the threshold speed, the movement speed of the grinding wheel 35 becomes the threshold-corresponding speed. When the operating speed of the X-axis handle 17a and the Y-axis handle 18a is less than the threshold speed, the movement speed of the grinding wheel 35 changes according to the operating speed of the X-axis handle 17a and the Y-axis handle 18a.

[0094] (S216) In S216, the CPU22 calculates the distance D between the tip of the moving grinding wheel contour line A1 and the target workpiece contour line B (DXF line or template).

[0095] For example, if the target workpiece contour line B is a straight line, a straight line perpendicular to the target workpiece contour line B and passing through the tip of the grinding wheel contour line A1 is identified. Then, based on the coordinates of the tip of the grinding wheel contour line A1 and the coordinates of the intersection point of that straight line with the target workpiece contour line B, the separation distance D can be calculated.

[0096] If the target workpiece contour line B is an arc, the normal vector of the arc of the target workpiece contour line B that passes through the tip of the grinding wheel contour line A1 is identified. Then, based on the coordinates of the tip of the grinding wheel contour line A1 and the coordinates of the intersection point of that normal vector with the target workpiece contour line B, the separation distance D can be calculated.

[0097] (S218) In S218, CPU22 determines the magnitude of the separation distance D. If the separation distance D is greater than the detection width m1 (D > m1), the tip of the grinding wheel contour line A1 does not reach the attention position line C1 and the stop position line C2, as shown in Figure 10(a). In this case, the CPU 22 moves the processing of this program to S220.

[0098] If the separation distance D is less than or equal to the detection width m1 and greater than the detection width m2 (m1 ≥ D > m2), as shown in Figure 10(b), the tip of the grinding wheel contour line A1 has reached the attention position line C1 but has not reached the stop position line C2. In this case, the CPU 22 moves the processing of this program to S222.

[0099] When the separation distance D is less than or equal to the detection width m2 (D ≤ m2), the tip of the grinding wheel contour line A1 reaches the stop position line C2, as shown in Figure 10(c). In this case, the CPU 22 proceeds to S226 of the program's processing.

[0100] (S220) In S220, CPU22 sets the value of flag F1 to "0" and the value of flag F2 to "0". Then, CPU22 moves the processing of this program to S221. In S221, CPU22 displays the entire target work contour line B in the normal display mode. Then, CPU22 returns the processing of this program to S204.

[0101] (S222) In S222, CPU22 sets the value of flag F1 to "1" and the value of flag F2 to "0". After that, CPU22 moves the processing of this program to S224.

[0102] (S224) In S224, the CPU 22 highlights at least a portion of the target work contour line B in a second display mode. Specifically, the CPU 22 may highlight the entire target work contour line B, or it may highlight a predetermined range of the target work contour line B. After that, the CPU 22 returns to S204. Hereinafter, this highlighting in the second display mode will be referred to as a warning highlight. For example, when a warning highlight is performed while the target work contour line B is displayed in white or black on the image display area 13a, at least a portion of the target work contour line B is displayed in yellow. In Figure 10(b), the portion of the target work contour line B that is being highlighted with a warning is drawn with a double line for the sake of explanation. The warning highlight may also be a blinking display. The predetermined range is, for example, the range that includes the coordinates of the intersection point on the target work contour line B obtained when calculating the separation distance D.

[0103] Furthermore, when displaying a warning highlight, the CPU 22 may notify the operator by voice or other means that the grinding wheel 35 is approaching the workpiece W. (S226) In S226, CPU22 sets the value of flag F1 to "1" and the value of flag F2 to "1". After that, CPU22 moves the processing of this program to S228.

[0104] (S228) In S228, the CPU 22 highlights at least a portion of the target work contour line B in a first display mode that is different from the second display mode. After this, the CPU 22 returns the processing of this program to S204. Hereinafter, this highlighting will be referred to as warning highlighting. In Figure 10(c), the portion of the target work contour line B that is being highlighted with warnings is drawn with a double line for the sake of explanation.

[0105] The warning highlighting includes, for example, changing the color of target work contour line B, changing the brightness of target work contour line B, changing the thickness of target work contour line B, changing the line type of target work contour line B, or a combination thereof. Furthermore, if the caution highlighting causes target work contour line B to flash, the warning highlighting includes increasing the flashing frequency of target work contour line B.

[0106] For example, if the target work contour line B was displayed in yellow in the caution highlighting mode, it will be displayed in red in the warning highlighting mode. Warning highlighting can attract the worker's attention more strongly than caution highlighting.

[0107] Furthermore, when displaying a warning highlight, the CPU 22 may also notify the operator by voice or other means that the grinding wheel 35 is very close to the workpiece W. <Rough machining of workpiece W by manual operation> The case in which rough machining of the workpiece W is performed by manual operation by the operator will be explained with reference to Figures 10(a) to 10(c).

[0108] (Normal display, caution highlight display, warning highlight display, and stop) Figure 10(a) shows the state where the tip of the grinding wheel contour line A1 has not reached the attention position line C1 (D>m1). In this state, when the removal process stop program shown in Figures 8 and 9 is started, flags F1 and F2 are reset in S202. Therefore, the process proceeds to S210 after the determination in S208. When the X-axis handle 17a and Y-axis handle 18a are operated, the CPU 22 moves the grinding wheel 35 at a movement speed corresponding to the operation signal, and moves the grinding wheel contour line A1 on the image display area 13a in synchronization with the grinding wheel 35.

[0109] In S216, the separation distance D is calculated when the tip of the grinding wheel contour line A1 has not reached the attention position line C1. Therefore, in S218, it is determined that the separation distance D calculated in S216 is greater than the detection width m1. Then, in S220, the value of flag F1 is set to "0" and the value of flag F2 is set to "0", after which the program returns to S204.

[0110] The normal control, consisting of steps S204, S206, S208, S210, S216, S218, and S220, is repeated as described above until the tip of the grinding wheel contour line A1 reaches the attention position line C1. During the execution of this normal control, the display control unit 25 normally displays the target workpiece contour line B.

[0111] When the tip of the grinding wheel contour line A1 reaches the attention position line C1, the separation distance D calculated in S216 is less than or equal to the detection width m1 and greater than the detection width m2, so the process proceeds to S222, and the value of flag F1 is set to "1" and the value of flag F2 is set to "0".

[0112] Then, in S224, a warning highlight is displayed on at least a portion of the target work contour line B (see Figure 10(b)). After that, the program returns to S204.

[0113] After this, attention control consisting of steps S204, S206, S208, S212, S216, S218, S222, and S224 is repeated until the grinding wheel contour line A1 no longer intersects with the attention position line C1, or until the tip of the grinding wheel contour line A1 reaches the stop position line C2.

[0114] During the execution of this attention control, if the operating speed of the X-axis handle 17a is greater than or equal to the threshold speed, in S212, the movement speed of the grinding wheel 35 is limited to the threshold-corresponding speed. When the operating speeds of the X-axis handle 17a and the Y-axis handle 18a are below a threshold speed, the movement speed of the grinding wheel 35 changes according to the operating speeds of the X-axis handle 17a and the Y-axis handle 18a.

[0115] Furthermore, while attention control is being performed, the CPU 22 (display control unit 25) continues to display the attention highlight of the target work contour line B. When the tip of the grinding wheel contour line A1 reaches the stop position line C2, the separation distance D calculated in S216 becomes less than or equal to the detection width m2. Therefore, the program proceeds to S226, where the value of flag F1 and the value of flag F2 are set to "1". Then, in S228, a warning highlight is displayed for at least a portion of the target work contour line B (see Figure 10(c)). After that, the program returns to S204.

[0116] After this, warning control consisting of steps S204, S206, S208, S214, S216, S218, S226, and S228 is repeated until the tip of the grinding wheel contour line A1 moves away from the stop position line C2.

[0117] In S214, if the operation signals (pulse signals) of the X-axis handle 17a and Y-axis handle 18a do not move the grinding wheel contour line A1 away from the target workpiece contour line B, the CPU 22 stops the grinding wheel 35 and also stops the grinding wheel contour line A1 in synchronization with the stopping of the grinding wheel 35.

[0118] If, during warning control, the operation signals (pulse signals) of the X-axis handle 17a and Y-axis handle 18a continue not to move the grinding wheel contour line A1 away from the target workpiece contour line B, the warning highlighting of the target workpiece contour line B will continue, and the grinding wheel contour line A1 (AR grinding wheel) and the grinding wheel 35 will remain stopped.

[0119] During the execution of warning control, assume that the operation signals (pulse signals) of the X-axis handle 17a and Y-axis handle 18a cause the grinding wheel contour line A1 to move away from the target workpiece contour line B. Then, in S214, the CPU 22 moves the grinding wheel 35 away from the target workpiece contour line B in response to the operation signals, and simultaneously moves the grinding wheel contour line A1 (AR grinding wheel) away from the target workpiece contour line B in synchronization with the grinding wheel 35.

[0120] (Effects and workings of the embodiment) In this embodiment, the following actions and effects are achieved. (1) The NC grinding device 10 (removal processing device) includes a display 12 (display unit) that displays the grinding wheel contour line A1 (removal tool contour line) of the grinding wheel 35 (removal tool) that removes a portion of the workpiece W, and the target workpiece contour line B of the workpiece W. The NC grinding device 10 includes an X-axis handle 17a and a Y-axis handle 18a (manual operation unit) that are operated by an operator to move the grinding wheel 35, and an NC control unit 29 (control unit) that moves the grinding wheel 35 based on the operations performed on the X-axis handle 17a and the Y-axis handle 18a. The NC grinding device 10 includes a display control unit 25 that displays the position of the grinding wheel contour line A1 on the display 12 in synchronization with the position of the grinding wheel 35 in accordance with the movement of the grinding wheel 35. The NC grinding device 10 includes a determination unit 26 that determines whether the separation distance D between the target workpiece contour line B and the grinding wheel contour line A1 is less than or equal to the detection width m2 (removal prohibition separation distance). If the determination unit 26 determines that the separation distance D is less than or equal to the detection width m2, the NC control unit 29 stops the grinding wheel 35 even if an operation is performed on the X-axis handle 17a and Y-axis handle 18a to move the grinding wheel contour line A1 closer to the target workpiece contour line B.

[0121] As a result, when removing a portion of the workpiece by manual operation, if the separation distance D is less than or equal to the detection width m2, even if an operation is performed on the X-axis handle 17a and Y-axis handle 18a to move the grinding wheel contour line A1 closer to the target workpiece contour line B, i.e., to move the grinding wheel 35 closer to the workpiece W, the grinding wheel 35 will stop, thus preventing excessive removal.

[0122] (2) When the separation distance D is less than or equal to the detection width m2, the display control unit 25 highlights at least a portion of the target work contour line B in the first display mode. This notifies the operator that the grinding wheel 35 has been stopped.

[0123] (3) The determination unit 26 further determines whether the separation distance D is greater than the detection width m2, which is the separation distance to prohibit removal, and less than or equal to the detection width m1, which is the separation distance to indicate caution. The NC control unit 29 moves the grinding wheel 35 faster the faster the operation performed on the X-axis handle 17a and the Y-axis handle 18a is performed. If the separation distance D is greater than the detection width m2 and less than or equal to the detection width m1, the NC control unit 29 limits the movement speed of the grinding wheel 35.

[0124] By limiting the movement speed of the grinding wheel 35, the separation distance D becomes less than or equal to the detection width m2, thereby suppressing the movement of the grinding wheel 35 due to its inertia when stopping the grinding wheel 35. (4) When the separation distance D is greater than the detection width m2 and less than or equal to the detection width m1, the display control unit 25 highlights at least a portion of the target work contour line B in a second display mode different from the first display mode. This allows the operator to be notified that the grinding wheel 35 is about to stop.

[0125] (5) The NC grinding machine 10 includes an imaging unit 39 that images the workpiece W and the grinding wheel 35 to acquire a real workpiece image Wg and a real grinding wheel image Tg (real removal tool image). The display control unit 25 displays the real workpiece image Wg superimposed on the target workpiece contour line B and the real grinding wheel image Tg superimposed on the grinding wheel contour line A1 on the display 12. This allows the removal process on the workpiece W by the grinding wheel 35 to be visually confirmed in a more realistic manner.

[0126] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined and implemented to the extent that they do not contradict each other technically.

[0127] In the above embodiment, the actual workpiece image Wg may be displayed on the display 12 without being superimposed on the target workpiece contour line B. Similarly, the actual grinding wheel image Tg may be displayed on the display 12 without being superimposed on the grinding wheel contour line A1.

[0128] In the above embodiment, if the separation distance D is greater than the detection width m2 and less than or equal to the detection width m1, at least a portion of the target work contour line B may be highlighted in the first display mode. Alternatively, if the separation distance D is greater than the detection width m2 and less than or equal to the detection width m1, at least a portion of the target work contour line B may not be highlighted; that is, the target work contour line B may be displayed normally.

[0129] In the above embodiment, if the separation distance D is less than or equal to the detection width m2, it is not necessary to highlight at least a portion of the target work contour line B. In the above embodiment, the material removal device was implemented as an NC grinding device. Alternatively, the material removal device may be implemented as a cutting device or a polishing device. In a cutting device, a cutting tool can be used as the material removal tool. In a polishing device, a polishing tool can be used as the material removal tool.

[0130] In the above embodiment, the grinding wheel contour line creation unit 28 creates removal tool contour data based on a grinding mark image, which is a removal mark image captured by the removal tool. Alternatively, the grinding wheel contour line creation unit 28 may create removal tool contour data based on an image captured by the imaging unit 39 of the tip of the grinding wheel, which is the removal tool. This allows the cutting edge shape and position of the removal tool on the machine coordinate system to be determined.

[0131] Furthermore, the creation of removal tool contour data is not limited to methods based on removal trace images or captured images of the tip of the removal tool. For example, by using a distance image sensor or a laser displacement sensor built into a camera as the imaging unit, the distance between the tip of the removal tool and the sensor can be measured, and the removal tool contour data can be created based on this measurement result. For example, a distance image obtained from a distance image sensor includes distance information for each pixel (distance between the tip of the removal tool and the sensor). The distance image corresponds to the captured image.

[0132] In the above embodiment, when the operating speed of the X-axis handle 17a and the Y-axis handle 18a is greater than or equal to a threshold speed, the movement speed of the grinding wheel 35 is limited to a threshold-corresponding speed, which is a constant value. That is, by setting an upper limit on the movement speed of the grinding wheel 35, the movement speed of the grinding wheel 35 when the separation distance D is greater than the detection width m2, which is the separation distance that does not allow removal, and less than or equal to the detection width m1, which is the separation distance that requires attention, is limited compared to the case where the separation distance D is greater than the detection width m1. However, the embodiment is not limited to this, and the grinding wheel 35 may be moved at a speed obtained by multiplying the movement speed of the grinding wheel 35, which corresponds to the operating speed of the X-axis handle 17a and the Y-axis handle 18a, by a reduction factor. The reduction factor is any value greater than "0" and less than "1". That is, the movement speed of the grinding wheel 35 may be limited over the entire speed range. In this modified example, regardless of the operating speed of the X-axis handle 17a and the Y-axis handle 18a, the movement speed of the grinding wheel 35 can be restricted when the separation distance D is greater than the detection width m2, which is the separation distance where removal is prohibited, and less than or equal to the detection width m1, which is the separation distance where caution is required, compared to when the separation distance D is greater than the detection width m1. Therefore, when the grinding wheel contour line A1 approaches the target workpiece contour line B from a state where it has approached it to a certain extent, the movement speed of the grinding wheel 35 slows down, allowing the operator to be notified that the grinding wheel 35 will stop.

[0133] Furthermore, it is not necessary to restrict the movement speed of the grinding wheel 35 when the separation distance D is greater than the detection width m2, which is the separation distance where removal is prohibited, and less than or equal to the detection width m1, which is the separation distance where attention is required. The area between the caution position line C1 and the stop position line C2 shown in Figure 10(a) may be further divided by multiple lines parallel to the target workpiece contour line B. In this case, the limiting travel speed may be set to a slower rate each time the tip of the grinding wheel contour line A1 reaches a position line close to the target workpiece contour line B. [Explanation of Symbols]

[0134] 10...NC grinding machine (removal processing machine), 11...Control device, 12...Display (display unit), 17a...X-axis handle (manual operation unit), 18a...Y-axis handle (manual operation unit), 25...Display control unit, 26...Determination unit, 29...NC control unit (control unit), 35...Grinding wheel (removal tool), A1...Grinding wheel contour line (removal tool contour line), B...Target workpiece contour line, D...Separation distance, m1...Detection width (caution separation distance), m2...Detection width (removal prohibition separation distance), Tg...Grinding wheel actual image, W...Workpiece, Wp...Dummy workpiece, Wc...Grinding marks

Claims

1. A removal tool for removing a portion of the workpiece, A display unit that displays the outline of the removal tool, which is the outline of the removal tool, and the outline of the workpiece after processing, which is the outline of the workpiece. A manual operation unit operated by an operator to move the removal tool, A control unit that moves the removal tool based on an operation performed on the manual operation unit, A display control unit that displays the position of the removal tool contour line on the display unit in synchronization with the position of the removal tool, in accordance with the movement of the removal tool, The system includes a determination unit that determines whether the distance between the target workpiece contour line and the removal tool contour line is less than or equal to the removal prohibition distance, If the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the control unit stops the removal tool even if the manual operation unit performs an operation to move the removal tool contour line in a direction that brings it closer to the target work contour line, in a removal processing apparatus.

2. If the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the display control unit highlights at least a portion of the target workpiece contour line, as described in claim 1.

3. The determination unit further determines whether the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance which is greater than the removal prohibition separation distance. The control unit is configured to move the removal tool faster the faster the operation performed on the manual operation unit is performed. The removal processing apparatus according to claim 2, wherein, when the determination unit determines that the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance, the control unit limits the movement speed of the removal tool compared to when the determination unit determines that the separation distance is greater than the caution separation distance.

4. When the determination unit determines that the separation distance is less than or equal to the removal prohibition separation distance, the first display mode is one in which at least a portion of the target work contour line is highlighted. If the determination unit determines that the separation distance is greater than the removal prohibition separation distance and less than or equal to the caution separation distance, the display control unit highlights at least a portion of the target work contour line in a second display mode different from the first display mode, as described in claim 3.

5. The system further includes an imaging unit that images the workpiece and the removal tool to acquire actual images of the workpiece and the removal tool. The removal processing apparatus according to any one of claims 1 to 4, wherein the display control unit displays the actual workpiece image superimposed on the target workpiece contour line, and the actual removal tool image superimposed on the removal tool contour line.

6. A removal processing method in a removal processing apparatus, wherein the removal processing apparatus is A removal tool for removing a portion of the workpiece, A display unit that displays the outline of the removal tool, which is the outline of the removal tool, and the outline of the workpiece after processing, which is the outline of the workpiece. The removal process method comprises a manual operation unit operated by an operator to move the removal tool, and the removal process method is Based on the operation performed on the manual operation unit, the removal tool is moved, In accordance with the movement of the removal tool, the position of the removal tool contour line on the display unit is displayed in synchronization with the position of the removal tool. To determine whether the distance between the target workpiece contour line and the removal tool contour line is less than or equal to the removal prohibition distance, A removal process method comprising: stopping the removal tool even if the manual operation unit performs an operation to move the removal tool contour line in a direction that brings it closer to the target workpiece contour line, when it is determined that the separation distance is less than or equal to the removal prohibition separation distance.

Images